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Monday, 31 March 2014

Scientists love going to conferences. Conferences are the only dream of academia that comes true. The young novices who stagger drooling towards the glittering attractions of academic life are disappointed to find when they reach them that they were all mirages -- except for the conference. To the PhD student the conference is simultaneously the most exotic and most legitimate way to avoid work on their research. To the tenured professor it is the only legitimate way to avoid all the work that is not research.

The conference is a professor's opportunity to convince themselves that they aren't just another white-collar worker who spends their days in painful tedious meetings in their office, longing for those precious hours of release when they get to leave their office and attend painful tedious meetings elsewhere. When their neighbours ask, "How's work?" they usually have no more to offer than a stock variant on, "Busy." Sometimes they even begin to entertain the frightening possibility that they aren't any more special than ordinary people. When a conference is approaching, however, their conviction in their exceptionality returns, and they can bask in some luxurious mock exasperation. "Oh, it's terrible. I'm just rushed off my feet. Need to get ready for a conference in Buenos Aires next week."

This is not all bluff. It is crucial that the professor have results to present; it is a matter of survival. Not professional survival, of course; the acquisition of tenure has removed any need for the pretence of productivity. No, we're talking about something far more terrifying: survival of the ego. To turn up at a conference without results to crow about is like a painter who's struggling in the midst of a confused canvas, and decides to take a break and visit a museum. And what's in the museum? Hundreds and hundreds of paintings that are all finished! It is just chock full of examples of what real artists can do, and how easily they can do it. The tortured painter can tell immediately, with professionally trained depressed eyes, that all of these accomplished bastards in the Impressionist wing just trudged out one morning into the fields, propped up their easels in front of a lopsided farmhouse or an especially gnarled tree, dabbed away for a few hours, and then caught a cab directly to the museum.

A conference is even worse, because, at the end of each scientist's presentation of their latest breakthrough, they will casually list the 5-10 major problems that they plan to solve before the next conference. Hapless Professor Useless begins to panic. That idiot I scooped last year is now six months ahead of me! And another six months from now, every outstanding question in my field will be solved! The last slide of every talk is inevitably and erroneously titled, "Outlook", but instead of taking comfort in their clumsy ineptitude at basic English usage, Professor Scrapheap realizes that they are correct: they have very precisely forecast the bleak outlook for his own career. After a week of sitting through this onslaught of others' accomplishments, Professor Hasbeen is convinced that within a year all of human knowledge will be complete, and scientific research of any kind will be relegated to historical curiosity.

The bottom line: it is essential that professors can spend the entire conference absorbed in their own results, and need have no fear that their delicate sensibilities will be upset by having to listen to anyone else's.

The situation is not quite so dire for the student. In fact, the potential to use recent results as leverage to argue for permission to attend a conference, acts as pretty much the student's only motivation to complete any work at all. Science is all about performance, in which the coveted role of genius is the academic equivalent of playing Hamlet; but, as an earlier exercise in theatrical delivery, the apprentice must make it successfully through a straight-faced presentation of the scientific case for spending a week in Florence. The key prop in this performance is a scientific result to present, or at least -- let's be realistic -- the potential for a scientific result. The reticent beginning student will be unable to believe that such a ploy could ever work, but the experienced student (and a PhD can be extended to such absurd lengths that students become extremely experienced) knows that this conference junket is a win-win situation for both them and their advisor. Not only is the student out of the advisor's hair for a week, but there is a fantastically high probability that the student will now finally produce some results, in some cases even as large as 8%.

Let's assume that results are indeed forthcoming. Professor and student can both relax, and look forward to the fantasy of a jet-setting lifestyle. The passport, the one piece of carry-on luggage (only amateurs check in bags), the clear plastic bag of toiletries. Set the phone to the new time zone immediately after take-off, select a pre-dinner cocktail, then carefully schedule in-flight movies and sleep to alleviate jet-lag. Yes, you're practically a high-flying business executive, or a diplomat, albeit the modest, self-effacing kind who declines First Class.

So we're off to a conference! On Thursday I'll let you know what it's like.

Thursday, 27 March 2014

In the last post I mentioned Richard Dawkins's The Ancestor's Tale, and it got me thinking. My main memory of that book is just as I described: an incredible intellectual experience. The book follows the path of human evolution in reverse. It works backwards from humans to our closest evolutionary ancestor, and then back to their closest ancestor, and so on, all the way to the simplest organisms. When I started the book I was doubtful. Wasn't this going to be nothing more than a catalogue of creatures? A list of the features that made them different as you went back from one to the other? At the time I knew embarrassingly little about evolution. I thought it was just natural selection, plus time. It turned out that at every stage there was some amazing new scientific idea or biological mechanism. I'm trained in physics and I know almost no biology, so every page was a revelation.

The point about all this, though, is that when I was thinking about the book a few days ago, I realized that I couldn't remember a single thing about it. There was all this fascinating biology that I learned from it, except that I clearly didn't learn a thing at all: none of the details stuck. This is not meant as a backhanded criticism of the book. Not at all. In contrast to the content, I recall the sheer thrill of the book extremely clearly. That sense of my world simultaneously expanding and filling up with new wonders, the unique pleasure of previously small mildly curious topics bursting open into impossibly huge flowers of ideas. After childhood, that is a rare experience indeed.

Last night my son wanted me to tell him a story at bath-time and I decided to try my hand at explaining last week's big cosmology discovery. (This is not as outrageous a challenge as it might seem, compared to the more usual requests to concoct an impromptu adventure that includes Horrid Henry, Batman, and Scooby Doo.) We didn't get quite as far as the mechanism behind B-mode polarization of the cosmic microwave background due to primordial gravitational waves; there was a slight misunderstanding earlier on about the basics of the Big Bang. "And that's how the Big Bang made the world?" he asked. "It made the whole universe," I said. His eyes went wide. "The whole universe? Wow!" That was a "wow!" more astounded, more pure, more completely blown away than I have ever had the urge to express in my entire adult scientific career. "Wow!"s like that can spontaneously burst from children ten or twenty times in a single day. And I'm not just talking up my own offspring; all kids do that, even the stupid ones. By contrast that subdued adult joy when your world unexpectedly expands (with or without inflation) is an infrequent experience, and one that's difficult to forget.

Except that apparently it is all too easy to forget. I pulled The Ancestor's Tale off the shelf last night and glanced through it. I vaguely recognized the diagrams at the beginning of each chapter, illustrating where the last chapter's group of species meet their common ancestor in this chapter. But all of the facts, all of the ideas that were so incredible at the time of reading, they were all gone. So what was the point of reading it? This is not the same as asking what was the point of any of the pleasures in life, because the reading was not done simply for pleasure. There are drugs I can take if all I want to do is temporarily fire off a few neurons. The real pleasure comes in the permanent addition to my life; it's like spending a fortune to add an extension to your house, only to have it collapse a week later. And it's different to asking, "What is the point of life itself, since all of the lovely memories we store up in our lifetime disintegrate when we die?" We hope that at least in the time we have, we can learn some interesting things, which we can spend the rest of the time marvelling in and mulling over. But why learn anything if it's going to be gone a month later?

The cure for this quasi-metaphysical downer is quite simple. Learning requires repetition. If I read a book and find it interesting, I don't have to worry about remembering the contents: I just have to remember to read it again. Isn't that a waste of time? Couldn't I be reading something else instead? Sure, but then it's two books that get forgotten in a month, not just one.

There's a perfect related example that comes to mind. A couple of posts back I alluded to Conrad's Heart of Darkness. I can be sure that if I had read that book only once, I would have forgotten it completely. I have also read Conrad's Nostromo, and I don't remember a thing about it, except that there was, perhaps, a mine involved. I read Conrad's Lord Jim, too, and I'm not even sure if I finished it. But Heart of Darkness was different, because after I read it I watched Francis Ford Coppola's incomparable modern cinematic retelling, Apocalypse Now. A few years later some friends decided one evening to watch a double feature of Apocalypse Now and then the unique making-of documentary Hearts of Darkness, which Coppola's wife constructed from footage and recordings she'd taken during the production, some without her husband's permission. I've no idea if their marriage survived this exposé, but I'm hoping that he recognised that her achievement was at least as great as his own. The documentary is packed with astounding moments amid a backdrop of filmmaking chaos. And how do I remember this? Well, compared to some complicated biological phenomenon in The Ancestor's Tale, it's much easier to remember the anguished voice of Coppola after his wife tries to convince him that his film is just like a school essay that he hoped to get an A for, and instead he gets a B, and he cries out, "I'm going to get an F! This is an F!" On the other hand, I've also watched the documentary twice. Somewhere in there I also re-read the book and re-watched the movie. So it's not especially surprising if I remember all three extremely well.

Great, now that's all worked out. The only remaining problem is finding the time to do all this reading. The main text of The Ancestor's Tale is 614 pages. At my current rate I can manage about two pages per week, so it will take six years. That's fine -- it will be time well spent. Assuming the book is as good as I remember it.

Monday, 24 March 2014

Here's a question: if a scientist starts a blog, how long before they start arguing against religious fanatics and climate-change deniers? You know it's going to happen -- and why not? There's no harm in attracting a few more readers, and google's hit statistics count a click from a crazy the same as from everyone else. In my case it was only six weeks before these dull topics bubbled to the surface.

Why dull? It's a variant of that Samuel Johnson split: parts of those subjects are interesting, and parts of them are science; but the parts that are interesting have nothing to do with science, and the parts that are scientific are not interesting. Sure, evolutionary biology, which you can ship in by the container-load to argue against religion, is an extremely interesting subject, but it's hardly relevant. It does not provide direct scientific evidence for the nonexistence of God. You might think that evidence for the nonexistence of anything is hard to come by, but when you consider real scientific questions, it's very easy: you postulate that your particular doubtful phenomena does exist, and you measure it. For example, I can assume that there are some meaningful scientific statements related to religious belief, and go out and try to find them. One day I might discover an entire shelf of books on the subject (perhaps when I stumble into the public library in the lost city of Atlantis), but for now my measurement is zero. When you show me upper limits on the Deity Field, then we can start talking.

Now, obviously there is some science related to climate change, but it's not at all interesting. I'll explain. When I was an undergraduate physics student looking ahead to graduate school, and wondering what topic I might like to research, I looked through the list of research groups at various universities around the world. There were loads of fascinating subjects. Quantum gravity, cosmology, chaos. And all these wild phenomena, black holes, superfluidity, even people starting to study consciousness. But every so often there would be these little groups who studied grimy, dull, really boring-sounding topics, like "geophysics" and "atmospheric physics". I didn't even find out what they were, they sounded so dull. Well guess what? Those are the people now studying climate change. They are at the centre of the hottest scientific topic of the 21st century. So either I accept that I was seriously wrong, or I conclude that, deep down, climate change science is truly dull. Refusing to admit you're wrong is something those guys are entirely familiar with, so I'm sure they'll understand if I go with the latter.

Fine: but didn't I admit that there were parts of these topics that are interesting, they just have nothing to do with science? Yes, but I was leaving off some important qualifiers. They may be sociologically interesting -- it is certainly very interesting that so many people persist in beliefs for which we have not, after several centuries of staggeringly precise and deep measurements and observations of the natural world, obtained one single piece of evidence, and that some of those people are even smarter than I am. It may be politically interesting to engage in the struggle to convince the general public and, more importantly, their governments, of the imminent dangers of climate change, so that we can combat the effects with sufficient force and ingenuity that our long-suffering grandchildren will agree to our Facebook friend requests [1]. But these issues are not intellectually interesting. There are a few mildly interesting arguments for and against the existence of God, but for most of us their novelty wore off at age 15, with no clear resolution. The case for climate change is based on terabytes of data and thousands of lines of climate-modelling code, which I suspect few on either side of the debate have much familiarity with (I have certainly never pored over screeds of ocean-temperature data or attempted to construct a computer model of the Earth's climate), so in the end it comes down to weight of authority and personal abuse. And that's only at ground level. Up where it matters, it's all about political influence and funding. I've no doubt that's fun for those in the thick of it, but it's not very interesting to talk about.

So why are these things so tempting to talk about? Because it makes us feel important and useful: fighting superstition and saving the world! For a theoretical physicist to feel useful is a rather rare thing. The temptation is much like Hemingway going to fight in the Spanish Civil War. Do you feel inadequate as merely an alcoholic with a catchy prose style? Want to prove that you will risk your life in the fight for justice? Never fear: there's a bloody conflict less than a day's journey away! Arguing about climate change has an even loftier goal, with far less blood.

If there's a reward in it for my beloved ego, I'm sure I can find something interesting to peck at, just to feel like I'm taking part. There must be a way. By all accounts Richard Dawkins, who I name-dropped in the last post as well, in addition to engaging in daily hand-to-hand combat with creationists, also writes fascinating and beautiful books. The only one I've read is The Ancestor's Tale, and I can attest that it was indeed an incredible read and, in contrast to everything I've said so far, a fabulous intellectual experience. There's no discussion of religion anywhere, but as an oblique attack on religious belief it wipes the floor with, for example, the supposedly oblique defence of religious belief in The Brothers Karamazov [2]. So you don't have to spend all your time repeating the same basic arguments over and over, or even just trying to make them in a new way [3]. It's possible to raise the level of discussion, even if, for some of us, we can only manage it in the footnotes [4,5].

Notes.

1. I've never understood the selfish obsession with what out grandchildren will think of us. If they despise us, it will be for the same reason grandchildren always have: we give them terrible Christmas presents. - "What would I want with a critical edition of the complete novels of Dostoevsky?"- "What are you talking about? This is great stuff. They say -- in one of the critical essays at the end of the book, in fact -- that Dostoevsky's characters didn't live life, they burnt it. They didn't breathe regular air, but pure oxygen." - "You mean just like I do, if I mess up the adjustments in my breathing mask?" - "I think that's pushing this apocalyptic vision of the future a little too far." ↩

2. Did I just say that Dawkins is a better writer than Dostoevsky? That's going a bit too far. It's like saying that an applied mathematics textbook is better written than War and Peace, just because its author clearly has a better understanding of differential equations than whatever motivated Tolstoy to end his masterpiece with that disappointing 100-page diatribe on the calculus of Napolean. Or perhaps it read better before the advent of chaos theory? ↩

3. To digress yet further, and get back to Dostoevsky: I never could make sense of the claim that, after the Grand Inquisitor gave God a pummeling that wouldn't be matched until that glorious chapter in Catch 22a, the rest of the book as a quiet, but complete, rebuttal. I didn't see any rebuttal at all. Maybe I need to read it again? Once more I'm presented with that painful choice of how to divide up the limited reading time I have in my life. Do I re-read The Brothers K, or catch up with Game of Thrones? Tricky. ↩a Chapter 18, if you want to relive the experience. And you do.

4. With so much reliance on footnotes I'm liable to be accused of aping David Foster Wallace. For the record, I consider footnotes a sign of authorial laziness, which are only almost acceptable in the most casual and unpolished pieces of writing. A blog, for example.↩

5. I should add that I have the utmost respect for those who do have the patience to engage with vacuous arguments again and again. A good example is my old friend from graduate school,
Mark Rupright.↩

Thursday, 20 March 2014

One of the most basic tools in science is doubt. It's also one of the most fun. You get to question everything. Be sceptical, mistrust authority, find holes in arguments, nit-pick, never let go; in other words, be a dick. This of course can upset people with deeply held beliefs, especially religious ones, but that's even more fun. The more deeply and seriously a person believes something, the more entertaining their reaction when you mock them.

This was certainly one of my early motivations to become a scientist. Somewhere in that confusing fog of adolescence I saw an obvious (but now impossible to reconstruct) link between a career in science and religious mockery. As time went on, though, I began to see that my teenage glee at baiting Christians was not so much a sign of scientific integrity, as simple immaturity. I realized that I had to find a way to move on from being an immature dick, to being a thoroughly sensible, grown-up adult dick.

I was convinced that this process would become clear if I went to a public lecture by Richard Dawkins. In 1996 his book tour to promote "Climbing Mount Improbable" fortunately included New Zealand, and he gave a talk in Christchurch while I lived there. I'm sure you'll immediately realise why Dawkins would be a natural hero to my post-pubescent dork self, and a science celebrity without peer and a bona fide superstar. That's right: he's married to an actress who played one of the original Doctor Who companions. And indeed, there she was, right there in the front row of the lecture theatre, the second regeneration of Romana. Wow.

He also happens to be the author of bestselling books about evolutionary biology, and a notoriously militant atheist. He has legions of loyal fans. The man is the Colonel Kurtz of the evangelical born-again atheists, broadcasting direct from science's alleged heart of darkness. He would set me straight.

And it was indeed a stirring lecture for the strict physical materialist. He told the story of a mother who wrote to him that her little boy had read one of his books, and been devastated by the thought of what a cold and empty Universe we live in, if there is no God in it. He had responded, "That's how it is. Deal with it." Yeah, you tell 'em, Dicky boy! I was lapping it up. What a guy!

Then came question time. This was even better. A delegation of the local creationist crazies had turned up to air their views. It was pure entertainment: Christians being fed to a lion.

But then there was this question. A university academic asked, "I have a colleague in the Chemistry department who is a Christian. Is he still allowed to call himself a scientist?" Oooh. Now that was an interesting question. My atheist muscles had been strengthened by a session in the Dawkins gym, so my own answer would have taken a stern line: "To some extent, I would say No."

Such wishy-washiness wasn't enough for Dawkins. He pronounced that this charlatan could not claim to be a scientist at all. Science was the dispassionate and open-minded search for truth, while Faith represented bias and closed-mindedness at its very worst. End of story.

That was too much for me. For a moment I was stunned. Did he really think that the Science Police should be raiding the universities of the world, tracking down professors with religious beliefs and ripping off their scientist badges? (We all have little badges. We keep them hidden from the public, because they get jealous. They're very nice badges.) Probably he wouldn't go that far. At least, nobody asked him that question.

I wanted to cheer my ideological idol, but couldn't quite manage it. Yes, science as an intellectual discipline is based on hypothesis and experiment (or paradigms and falsifiability, if you prefer), and the progress of scientific discovery is most rapid if its practitioners have an open mind and are willing to disregard their prejudices and superstitions. But, regardless of the ideal, actual scientists do have prejudices and superstitions, some of which they are conscious and quite proud of, and others they are never even aware they have. Some of them believe in God, and some believe in far wackier things. And unless those beliefs stand directly in the path of the specialised topic they study, those scientists can make valuable, and even world-changing, contributions. Sometimes it's their irrational prejudices that lead to discoveries. (The most common, "I am right and you are wrong".) If this makes the science idealist squeamish, don't they deserve the same answer as Dawkins had for that dopey little boy's mother? That's how it is. Deal with it. I would love it if all scientists were shining examples to us all of clean, pure, rational thinking, and were kind and noble and honest as well, good-looking and with fresh minty breath, just as the creationists would love it if God created dinosaur fossils on one whimsical April 1st. But that's just not the way it is.

Let's not make too much of Dawkins' remark. It was an impromptu answer to a question, made almost 20 years ago. His true view might be more nuanced, or it might have changed. He also might be wrong: that happens, and that's Ok, and while on the comment board of a rant blog, that one statement might be taken as the basis for an all-caps, zero-grammar, incoherent hatchet job on the man's entire career, the rest of us can just file it away as a "teachable moment". And I'm certainly not going to needlessly incur the wrath of Dawkins' fans, chanting up there in the jungle; they would gladly hack me apart like a sacrificial cow.

And what did I learn from this teachable moment? Did I realise that, after all, we're all just trying to make sense of the world, and whether you're a scientist or a fundamentalist, your beliefs deserve respect and consideration?

Are you kidding? Of course not. I just realised that you should make fun of scientists as well.

Monday, 17 March 2014

Einstein is the hero genius of all humanity. For people like me, who study black holes, Einstein is even more of a hero; without him, the topic we've devoted our entire adult lives to simply would not exist. I have a little Einstein shrine in my office, where I pay thanks every day in the only way a working scientist knows how. "O great Einstein, how privileged I am to exist within your future light cone! As a humble token of my deep thanks, I vow to cite you three times today."

That makes it easy to forget that just like everyone else, Einstein both screwed up and covered up. A few years ago I heard a story that shrunk the Einstein myth to normal proportions. In 1936 he wrote a paper with Nathan Rosen, in which they demonstrated that gravitational waves are physically meaningless. Gravitational waves turned up in my crystal-clear explanation of Einstein's general relativity: they're wobbles in the shape of space and time itself, washing across the universe, signalling how objects have been zooming around. They're a crucial and natural part of the theory. Einstein and Rosen had considered what they thought would be a simple example of a long sheet of a gravitational-wave ripple, just like a dying ocean wave coming into shore, which you can see coming in all the way up and down the beach. The trouble with their example was that at some places along the beach, the dying wave exploded into a tsunami: the equations blew up in their faces. No matter what they did, the problem wouldn't go away. It was like pushing down an embarrassingly large bubble in a wall of wallpaper. Wherever they pushed it down, it popped up again somewhere else. Such things must be impossible, and so gravitational waves must not exist after all.

By that time Einsein was living in the United States (he had left Germany over a minor political disagreement that we need not go into), working at the Institute for Advanced Study in Princeton. He and Rosen sent their paper to the leading US physics journal and men's fitness magazine, Physical Review. The journal sent the paper to another scientist to referee. The anonymous referee then had the rare privilege to point out that Einstein had made a mistake. The journal had no choice but to return Einstein's work to him.

Einstein was furious. He wrote back, "I didn't send you the paper to check, I sent it to you to publish!" And with a charming petulant schoolboy flourish, added, "I'm never publishing in your journal again!" He then resubmitted the paper to the Journal of the Franklin Institute of Philadelphia, which treated the great man's work with the proper respect it deserved.

Now, the next bit is even better. It turns out that the referee was one Howard Percy Robertson, who was at Princeton University, which is entirely within prank-making distance of the Institute for Advanced Study. Robertson was no slouch himself, and was one of the people whose solution to Einstein's equations for the entire universe is what modern cosmologists spend all of their time failing to improve on.

Resplendent from having just given the world's most famous scientist the academic equivalent of a good slap, Robertson was strolling the corridors of Princeton soon afterwards. He ran into Leopold Infeld, who had just been hired as Einstein's new assistant. Robertson casually asked Infeld, "How's old Albert these days?"

"Furious!" replied Infeld. "Some scoundrel at the Physical Review has had the nerve to tell him his paper on gravitational waves is wrong."

Robertson did some frowning and scratching of his head. "I'm confused. Isn't this just a trick of the coordinates? That's always a problem in Einstein's theory."

"Great Scott, you're right!" cried Infeld, or whatever it is that you exclaimed in 1936 when you realised that Einstein had botched up. It wasn't the gravitational waves that were nonsensical, but Einstein and Rosen's choice of coordinates; they needed to cut their wallpaper better.

Infeld scurried back to Einstein, and told him what he'd learned from Robertson.

Einstein was a professional, and he knew how to handle this. "Well done, my dear Infeld. I was just now looking for you to tell you precisely the same thing. I was considering my result in more detail last night, and reached the same conclusion."

"I must congratulate you on being only one day behind my own calculations."

"Thank you very much, Herr Doctor Professor!"

"Now you must excuse me, I am scheduled to give a seminar on my proof of the nonexistence of gravitational waves."

Then, without a hint of hesitation, Einstein delivered an impromptu lecture on why his original proof was wrong, and chuckled over what a tricky phenomena these little gravitational waves were.

Afterwards Einstein returned to his office. It was clear what he had to do. He innocently asked his secretary, "Miss Dukas, do you happen to know where that referee report went?"

"The one you threw in the trash and set alight?"

"Um, yes."

"After I put out the fire in your office, I used the ashes to fertilise my roses. Would you like me to try and reconstitute it?"

"No, thank you. I expect I can reproduce the results more quickly myself."

He set to work, and managed to resolve the problems in his calculation just in time for the article's proofs to arrive from the Journal of the Franklin Institute. He crossed out the title, "Do gravitational waves exist?", and replaced it with, "On gravitational waves." He also replaced the conclusions ("No") with a wonderful new solution of the Einstein equations, which predicted an entirely new class of gravitational waves, from a cylindrical source. When he returned the proofs he included a small note apologising for the minor changes. The journal duly published the modified paper.

Robertson was tickled pink to see the published result, but did not have long to bask in his smugness. The Physical Review had just sent him another thorny paper to referee.

Postscript:

If you read Daniel Kennefick's Physics Today article, you may be surprised by how much of this story is actually true. It is more likely that you will be shocked at what terrible liberties I have taken with such venerable characters in the illustrious history of my field.

As for gravitational waves themselves, they were tricky to clear up in the theory, and they have proved even harder to verify experimentally. However, their reality was implied by observations from Hulse and Taylor in 1974, which earned them a Nobel Prize in 1993. And if the rumours are true, later today (yes, today!) there will be an announcement of new readings of that great cosmological cave painting, the CMB, that infer the existence of an especially fancy class of gravitational waves, which were produced in the aftermath of the Big Bang. (Update: the rumours were true.)

Beyond that, direct measurements of the little buggers are much harder. But we are working on it.

Thursday, 13 March 2014

Behold! At the end of the illusion I am now going to perform, any reader of this article of sufficient intellectual prowess to read the words, will completely understand the conceptual underpinnings of Einstein's general theory of relativity and gravitational waves.

How amazing is this feat? General relativity is one of the most famously incomprehensible theories in human history. A few years after Einstein published the theory in 1915, it was said that only three people in the world understood it. Now they are all dead. That's how hard this will be. But I will perform this incredible illusion right before your very screens.

We start with questions so deep that it is madness to believe we can answer them. What is gravity? Well, it's this effect that reputedly makes apples drop on Newton's head [1], and makes the Earth go around the sun. Yes, but what is it? What is pulling the apple towards the ground? Zombies reaching out of the soft orchard soil? A fine explanation, but that cannot be what also pulls the Earth in orbit around the sun. Are there little strings that we can't see? As we learnt in the last post from our grouchy friend Feynman, an explanation involving strings will only tie us in knots. We would like to know what is actually there, what is really doing this incredible job.

Now that we've set ourselves up for disappointment with such an impossible question, we're open to any crazy idea. Newton said there was just a "force". That hardly helps, and he wouldn't have been any more convincing than George Lucas, if he didn't also provide a handy formula to calculate it with. Lots of people were unconvinced. "Really? There's just this force, that magically crosses the wastes of space, in no time at all, and pulls the Earth around the sun? Are you kidding me?" But his little formula worked. No matter what the problem -- lots of planets, with moons and asteroids, all on crazy complicated orbits around the sun and each other -- it was possible to calculate exactly what they did with Newton's little formula. So in the end you just had to shrug your shoulders and pretend that everything had been explained after all.

Then along comes Einstein. He has his favourite idea, which is that nothing can travel faster than the speed of light. He's realised that this one idea is going to keep him in business for life. He looks at Newton's formula and he says, "Aha! This `force', whatever it is, mustn't travel faster than the speed of light. But where in Newton's formula does it say that? Huh? Where? There must be something missing."

So he goes back to the same impossible questions as before, and decides to roll in a few more. What is time? What is space? Now we're getting deep. A mystic can wallow in these deep questions for years, achieving nothing besides making a fortune peddling their babblings to other mystics. A scientist tries to be more concrete, and asks about things they can measure. We know how much space we have by measuring distances. We know how much time we have by measuring some duration of it. Have we explained anything? No -- but at least we've got some numbers!

Einstein's brilliant idea was to say that distances and times change depending on the objects that are around. If you buy yourself a quarter acre of space, and then fill it with some good heavy objects, the space itself will stretch, and you'll have more than a quarter of an acre. Plus, all of your cosmic bric-a-brac will slow down time as well, at least when you get close to pieces of it. It's quite a bargain.

Now, you might conclude from all this merely that Einstein had a dangerous drug habit. But no -- it turns out to be true. Clocks on Earth really do tick slower than clocks in space, and this is crucial to how GPS works. You can thank Einstein every time your phone helps you find a restaurant (but blame google when it doesn't) [2].

Ok, very good, space and time have limbered up. What about gravity? No problem. If objects were to stretch and curve and warp space and time in just the right way, then that would surely affect the way anything moves through space, and maybe that could be used to reproduce the effect of gravity.

If that sounds far-fetched, imagine rolling a ball across a trampoline. It goes straight across. Now get someone to stand in the middle of the trampoline, and roll the ball past them. The ball curves towards them. If you send it at just the right speed, it will circle right round them. By changing the shape of the trampoline mat, you can mimic gravity! You can even imagine that the ball doesn't even notice that the mat is stretched, and thinks it is travelling in a perfectly straight line.

If you don't quite get this last point, you can perform the following experiment at home. Get yourself a really big trampoline, and paint a large circle around the centre of the mat. Make it a dashed circle, like the lines on a road. Now put a light person in the centre of the circle, like a baby, except that the baby needs to be asleep, otherwise it will crawl away and mimic the nightmarish gravitational effect of the sun sticking the Earth in its mouth and possibly choking. Then attach wheels to your smartphone; phone cases with wheels are available from all good online retailers. Switch on the little video camera, and then roll the phone along the trampoline at just the right speed that it orbits around the sleeping baby. Now watch the video. The result will be a blurry mess, and you'll be utterly discouraged, but now you'll know what experimental science is like every day.

So now we have a picture of how Einstein thought gravity works. Would Feynman approve? I'm afraid not. "What the hell kind of explanation is that, you goddamn phoney! The reason the ball goes around the baby is the same as the reason a trampoline works in the first place -- gravity. So you've used gravity to explain gravity. That's the worst cheat I've ever heard!"

Ok, can I say that it's an even simpler effect? If I draw a straight line on a flat sheet of paper, it goes from one side to the other. But if I wrap the paper into a tube, then the line meets up with itself, just like a planet going in orbit.

"No you can't! Are you crazy? Anything that follows the line on the paper will travel the same circle, no matter how fast it moves, or how heavy it is. But things that orbit the sun would instead fly off into space if they went faster, or fall into the sun if they went slower or were heavier. So you haven't explained a thing! It's a fake!"

He's right. It's just an illusion. Einstein's theory says that space and time really are distorted by massive objects, and uses this effect to describe gravity. But there is no corresponding effect in everyday life; that's why the real theory is so difficult to understand.

Don't be discouraged. It's not just innocent bystanders who are told this guff. Generations of physicists have been trained on it as well, and among the shambling crowds of relativists who currently roam the Earth, most of them labour every day with these illusory pictures at the back of their minds. Many would be surprised to have got the finger from Feynman. That's Ok, because in the end it's Einstein's equations that they use for their calculations, and they work: they predict all of the same effects as Newton's formula, plus a few effects that Newton's formula didn't, which are entirely real and measurable. And all of these effects now travel at the speed of light, just as Einstein wanted. If some cosmic prankster plops a planet into space, its effects on space and time ripple out from it at the speed of light. Those ripples are called gravitational waves. If the same prankster took away the sun right now, the Earth would continue to orbit around nothing for a full eight minutes, until the new shape of space and time washed out across the solar system, and only then would the Earth fly away, feeling very alone, and especially cold.

Maybe you've concluded that this wasn't all so bad after all, and can't understand why Einstein's theory is famous for being so difficult. The difficult bit is getting all those distances and times straight. (Or curved, as it were.) You need coordinates, like the coordinates on a map. Now those coordinates can stretch and warp and twist. In fact, for Einstein's formulas to work, it's important that we can do just about any damn thing we like with the coordinates. But in the end we still also have to be able to work out actual distances and navigate the map. That's the part that gets hairy.

In the next post we'll see how this fooled Einstein himself. So tune in next time, folks: see Einstein get himself tangled in the net of his own coordinates, and then watch him escape!

Notes.
1. It's nice to think that Newton was just sitting in an orchard contemplating a life as an economist, before suddenly an apple fell on his head and he discovered gravity and his life changed forever. That's unlikely to be true. Although he did later work on monetary policy.↩

2. I've argued with scientists who believe that the best way to communicate Einstein's achievements to the general public is to point them to GPS. How depressing! "Why is Einstein one of the greatest minds in human history? Because he wrote an app."↩

Wednesday, 12 March 2014

A little interruption to my regular schedule, to rhapsodize over the wonders of the web, and YouTube in particular. In Monday's post I included a quotation from Feynman on the difficulty of explaining physics. I first read that quote in James Gleick's biography Genius back in 1994. It's an exceptional book, which I cannot recommend highly enough (except for all the science explanations, of course, which are always a drag).

The quote comes from a series of interviews recorded by Christopher Sykes for the BBC, for a documentary that eventually became "The pleasure of finding things out". I'm guessing that this particular section was not included in the documentary, because an endnote in my copy of Genius references it to an "untitled videotape" from those recordings. At the time I could not watch the original tape of Feynman, and I couldn't even watch the documentary, because it had not been released on video.

Now this "untitled videotape" can be found in an instant on YouTube, and you can delight in Feynman's gruff explanation, and conclude half way through that he really is being a bit of a jerk, and then be delighted all over again when he gets so excited as he approaches his conclusion that his eyebrows practically lift him out of his chair. I included a link on Monday, but here it is again. Enjoy!

Monday, 10 March 2014

I am going to tell you one of my favourite stories about a scientist revealing a gaping hole in the trousers of his superhero costume – about Einstein, no less – but unfortunately it will require me to explain some technical concepts, and I must offer a disclaimer in advance. Several disclaimers, in fact.

Explanations of any kind are a weighty responsibility. I have to be sure I really do know what I'm talking about, and there's nothing the human brain does better than convince you that you know what you're talking about. I was once entering a concert in Los Angeles that would include Tchaikovsky's 1812 Overture, which is probably one of the most famous and recognisable pieces of music in the Western world, and I overheard a little girl ask her mother what it was about. The mother confidently replied, "The War of 1812." If you read my last post, you'll guess that I did precisely nothing to correct either the daughter or her ditzy mother. All the experience did was burn a horrified memory into my brain, from whence it is broadcast back to you now.

The dangers of this sort of self-delusion are even greater when trying to explain complicated physical theories. In some cases I'm protected by a clear knowledge of my ignorance. For example, quantum mechanics. After my last quantum mechanics exam at graduate school, I was called into the professor's office, and he told me, "We're going to let you pass, but if ever in your future research you need to do any quantum mechanical calculations – don't! Get someone else to do it for you, because you obviously don't understand a thing."

This is the memory that flashes through my mind when some hapless student comes inexplicably to my office and says, "Excuse me, I'm having a problem with my quantum mechanics homework. Can you help?"

I'm immediately thrown into a panic, and will blurt out the first excuse that leaps into my mind.

"I'm sorry, I have to leave now to go and pick up my son from school."

"Now? It's only 11 o'clock in the morning."

"I have to get him early. He was stabbed in the playground."

"Stabbed!? Where to do you send him to school?"

"South Central LA."

"In America?"

"And what with the long flights from the UK, and dealing with huge Californian hospital bills, and nursing him back to health, and maybe rethinking our choices about his education, I expect to be away for the rest of the course. So ask your questions to someone else."

I only say this because I'm terrified they want help with some fiendish calculation involving Clebsch-Gordon coefficients. In reality they just want to know how to spell Schroedinger. But in matters of scientific explanation, it's always better to err on the side of caution.

With non-technical "popular" explanations it is far worse. Let's be honest here. You know and I know that popular explanations of science are a cheat. Any given scientific concept will be based on a host of other concepts, each of which requires days or weeks or longer of mulling over and confusion and "But what about..?", until you can finally delude yourself that you've made sense of it and move on. It requires years of training, and even among the seething ranks of tenured academics, there are only a handful who know what the hell they're talking about. So it is entirely dishonest, not to mention insulting, to sum up an entire research field in four sentences and then say with a smug smile, "Simple, huh?"

For an excellent illustration of these things, I turn, as one so often does, to good old Feynman, whose educational skills were a fantastic contradiction in themselves. He is famous as a great educator, yet trained an appallingly low number of graduate students. He wrote a classic series of entry-level university textbooks, which are notorious for being impossible to teach from. He claimed that if you couldn't explain a scientific concept to a child, then you didn't properly understand it. Yet he also provided what I consider one of the greatest examples of the difficulty of teaching scientific concepts to the uninitiated. When asked to explain how magnets work, he essentially refused:

If I said that magnets attract as if they were connected with rubber bands, I would be cheating you, because they're not connected with rubber bands… If you were curious enough you'd ask me why rubber bands tend to pull back together again, and I would end up explaining that in terms of electrical and magnetic forces – which are the very things I was using the rubber bands to explain, so I have cheated very badly, you see.

This very quotation ran through my head when my seven-year-old son asked me how magnets work. If he was stuck in a hospital bed for several weeks recovering from stab wounds, perhaps I could have come up with something reasonable, but I'm told that this is not the right attitude to parenting. Instead I simply stood in front of him for a full thirty seconds with my mouth hanging open, until he decided to go and find a normal parent to play football with.

It's no better when I come across someone in a pub who exclaims, "I love physics! I know all about Professor Hawkins, and I've watched all of the TV shows from Professor Brian Cox! I find physics fascinating!"

The classic wits of centuries past would have known how to respond. Churchill wouldn't have hesitated to remove his cigar from his mouth, puff out his chest, and agree, "Physics truly is fascinating, sir, but you are not."

I'm left trying to explain black holes. A black hole is an object with a gravitational pull so strong that even light cannot escape. Why can't light escape? Because the escape velocity is greater than the speed of light, and nothing can go faster than the speed of light. Why not? Because Einstein worked out that this is a logical consequence of Maxwell's theory of electromagnetism, which predicts the same speed of light in vacuum, irrespective of your relative velocity to the source. And why does Maxwell's theory predict that? That's an extremely good question, and I'm afraid I don't know the answer, and I doubt I can find out right now while we're talking here in this pub.

But it's unlikely we'll have got to such a deep level, because my intrepid interlocutor was very likely either (a) one of those irritating people who try to convince you that surely things can travel faster than the speed of light, it's just that we haven't worked out how yet, or (b) an ordinary human being who was lost at "escape velocity" and has realised that making sense of this could take many months indeed, and, anyway, much like Forster's Mrs Munt, they've secured their nut, in the form of a one-line description of a black hole that might come in handy one day in a pub quiz, and now they're ready to go off and find a normal person to talk football with. Plus, that wasn't even very technical – the same explanation could have been delivered by an above-average high school student or a below-average university graduate. What would happen if I were to try and explain the subtleties of a scientific argument that even Einstein got wrong?

I suppose we'll find out in my next post, when I try to do exactly that. Just don't expect me to do it very well.

Thursday, 6 March 2014

I like to think of myself as a complete jerk, but in reality the "complete" is an exaggeration. I'm usually too chicken to pull it off. People will say stupid things about science, things that I know immediately are positively moronic, and I am too polite to tell them. Afterwards I feel guilty. If an actual scientist won't correct them, who will? Worse than that: by letting them get away with their crazy notions, haven't I effectively encouraged them? When some braver individual tries to set them straight, can't they now say, "What do you know? Mark agreed with me, and he's a real scientist."

I once talked to an old lady who was very excited to hear that I study black holes. "I've seen a black hole!" she told me. She had seen one through a telescope at an astronomical observatory she visited while on holiday.

I expressed mild, but polite, surprise. She attested that it was indeed true. Then we moved on with the conversation.

She was an elderly relative, so I probably earn points amongst normal people in the category of, "Awkward scientist who managed to restrain his embarrassing tendencies in a social situation." But as a scientist, I feel like I failed.

I should have told her, "Black holes are not called black for nothing, and space is rather dark, too, so anything you saw was, pretty much by definition, not a black hole. In fact, you gullible old trout, the real definition of a black hole is an object so compact and gravitationally powerful that light cannot escape -- so, of the many and varied exotic astronomical objects you might have seen through this telescope, a black hole was certainly not one of them!"

I should then, as a diligent defender of scientific truth and integrity, extracted from her the name of this observatory, if not her specific tour guide, and paid them a personal visit to ensure that they were not telling lies to sweet old ladies. ("You can't see anything through the telescope? No, don't worry dear, you're doing it right. You're looking at a black hole.") And if they were, I would come back with a gang of science heavies, and bust their kneecaps. I'm sure my research grant includes funds for this purpose. And I believe the observatory in question was in Hawaii.

I can understand that there are times when it's best just to let it go. But it is precisely at such moments when people spring their stupidities on me. For example, at my father's funeral, of all times, I was chatting with an old guy who said, completely out of the blue, "That whole global warming thing has got to be rubbish, doesn't it?" I made an especially mild protest, "Well, they probably know what they're talking about." He waved it aside. "I've lived for many years, and never seen anything like it. It's a load of rubbish." What was I supposed to do? Give this old friend of my father's, who, let's face it, had probably had a bit of a rough day, a thorough intellectual shredding? Maybe I should have. Wasn't it he who was upsetting me with his softheaded presumption that 80-odd years of ignorance integrates up to a wise old man? It hadn't been a very jolly day for me, either; maybe it was just the psychological therapy I needed, to leave this old duffer stunned in the corner with his weak tea and his cold sausage roll. If Nathan Zuckerman can explain the Big Bang and the futility of human existence on his own father's deathbed, what possible excuse could I have, apart from the flimsy one that he is a fictional character?

Plus, I'm just as much a gutless coward even when there isn't the excuse of an inappropriate social situation. I cannot count the number of times someone has said to me, "Oh, you study physics? That's great. I've just been reading about quantum mechanics. It has so much to say about our minds and spirituality." These people are not relations of even the most distant variety. They are not friends of friends, and they are not currently suffering any intense emotional trauma, beyond having to live daily with the curse of stupidity.

Examples are numerous, but my favourite was a talkative Irish taxi driver. I especially liked him, because I had not, after an entire year of living in Cork, encountered such a wonderful embodiment of a stereotypical Irishman. It was only after moving to another country, and returning for a visit, that I came across this fellow driving me from the airport. It's quite possible that an army of these guys had been laid on deliberately by the tourist office in yet another ill-conceived and thoroughly oblique effort to combat the financial crisis. He was of course fascinated to hear that I was a physicist, and just frothing with joy to talk about black holes and the big bang and other distant signs of God's power. "You know I'm a Catholic," he told me, "and I just have to wonder, What is God trying to tell us with these black holes?"

I can honestly say that this is not a question I had ever asked myself before. It was not, strange as it might seem to him, covered in any textbooks. The leading research journals were silent on the subject.

I have no idea what I babbled at him. I might even have humoured him with some fluff about black holes being a sign of the vastness and immensity of God's Creation. I was within only miles of the Blarney stone at the time -- surely I could be forgiven? What I certainly did not do was point out that, if anything, black holes were part of an astounding collection of evidence that his worldview was about 2000 years out of date, and maybe he should make a little effort to catch up.

It's moments of shame like this that make me think of the example of tougher scientists. What would Richard Dawkins have done? That's easy: Richard Dawkins would have been ejected from the taxi, probably while it was still moving.

The problem is that one of the greatest attractions of science, besides learning how the universe works and all that, is that it provides an excuse to avoid other human beings. And especially, to avoid simple-minded human beings who haven't bothered to acquire the basic understanding of the natural world that humanity has possessed for at least the five generations before they were even born. All this "public communication of science" stuff is telling me that now that I've got myself a nice quiet university office to snooze in for the rest of my life, I actually have to get up and go out and "engage" with these moronic masses. And try to do it politely. Well, all right then, if I must. But only during working hours. On evenings, weekends and public holidays, I'll nod and smile through whatever tosh I'm told.

Monday, 3 March 2014

To anyone thinking of being an academic, I highly recommend it. The flexible hours, the long holidays, the international conferences, not having to wear a suit: yes, being an academic is fantastic. Becoming an academic, however, is a nightmare. That's the whole point. How could we academics feel so privileged and superior if anyone could do it? In fact, we go much further than that. We get a truly wild giddy joy from the knowledge that practically no-one can do it. How do we know that? We repeat over and over the experiment of convincing smart, creative, ambitious, hard-working young people to begin a career in academia, and then watch them fail.

Is it cruel to encourage these hopeless dreams? Not at all. Having your infantile dreams relentlessly beaten out of you is what growing up is all about. Plus, when you do finally face reality, there are plenty of perfectly fine normal jobs waiting for you. That's the difference between trying to become an academic and trying to become a movie star. Budding movie stars flock to Hollywood. They work until they drop, demean and degrade themselves, forgo any hint of a personal life, alienate their family and betray their friends, and do that for year after year after year, until finally they either give up entirely and become a gibbering loser back in their old home town; or they enter the porn industry. Academia is just like that, except that the loser bit is replaced by, "respectable well-paying job", although sometimes still with the gibbering. The equivalent of the porn industry varies between disciplines; for failed physicists it's Finance.

Also: they are all given plenty of warning. Usually it comes just before that dire decision to begin a PhD.

I was warned early. When I was still at high school a chemistry teacher told me, "You don't want to do a PhD. You'll be 30 and still living in a dingy flat with mis-matching furniture." But who would ever trust the career judgement of someone who became a schoolteacher?

Later, as I was completing my undergraduate physics degree, a professor called me into his office and gave me more anti-PhD and anti-academia warnings. With tears in his eyes he told me tales of idealistic and brilliant young scientists who were now many years into temporary postdoctoral research posts, with families to support and no permanent job on the horizon. I waved aside his objections and walked out of his office. If I'd stayed I'm sure he would have signed me up to go door-to-door raising money for the "Help the physicists" charity, aimed at supporting those impoverished physicists who had reached the very edge, who could barely hold on any longer and who were, quite honestly, on the verge of giving up and getting rich. He probably expected the standard response to be, "Damn, I've just given all my money to help the blind and cure cancer; I should have kept it for you!"

People tried to save me even after I moved to America to start my PhD. I was alerted to the dangers by a senior postdoc, who was reputed to be a true genius who had done incredible work in quantum gravity, but had been a postdoc for over a decade. He was holding out for the permanent job that his supervisor had promised to arrange for him, but unfortunately his supervisor's raving-lunatic act turned out to be more than an amusing affectation, and no job was forthcoming. He told me, "If you love physics and want to do a PhD just for the fun of it, that's fine, so long as you're sure you don't mind wasting five years of your life." He clearly had no idea what he was talking about. I knew what I was doing. Not only was I being paid to live and travel in the United States, I was even given a high-speed internet connection during those blissful first years of Napster. I had my priorities clear.

Once the PhD is complete, there are no more warnings. If you don't quit then, everyone realises that you're beyond hope. Now it's just a waiting game. Will you successfully perform the mental contortions necessary to extricate yourself and at the same time believe that this was what you had planned all along, or will you just scream "Fuck it!" one day and remain twisted and scarred for the rest of your life? For the successful academics watching, this is the most tense and fascinating part. It's so rich in excessive human drama that I was tempted to write this entire blog in the guise of a frustrated and bitter ex-postdoc, venting his hilarious rage and riling against the evil machinations of the "system". But that seemed a little hypocritical. I thought of all the ex-physicists out there who would read it and think, "Shit! We quit academia, and he's still stealing our material!"

Is success possible? Certainly. But only if you remain fantastically naive. It is essential that, at each step, you weigh your options as honestly and carefully as possible, and then choose the most irresponsible path. Your worst enemies are clear-sightedness, a level head, and a sense of perspective. Your friends are arrogance, blindness and immaturity. And don't underestimate the importance of good advice: you need something to rebel against. The darkest days will be when you've discovered that you have become obsessed, think of nothing but work, can barely sleep, you are jealous and spiteful of all of your colleagues, your wife has started taking painkillers along with the booze, your kids are in counselling, and you have become utterly convinced to the depths of your miserable soul that permanent jobs go only to those who are limitlessly unscrupulous, sycophantic, and, ultimately and most galling of all, lucky.

That's the final hurdle: the question, "If I do get a permanent job, how will I ever live with myself, thinking of those crowds of the more talented and more deserving, who didn't make it?" Fear not. The human capacity for self-delusion is unbounded. The moment you achieve academic nirvana, the full truth will be revealed to you. "Yes!" you'll cry. "The system really does work after all! How just and fair and good it is! Now, get away from me you snivelling losers!"

There may be nagging pangs of guilt, but they will soon be pushed aside by a whole new problem: the rewards of academia aren't quite living up to your exalted expectations. Yes, you can stroll into the office at whatever hour you wish, or even decide to "work at home" whenever you feel like it. But you can also stay up all night writing grant proposals, and work all weekend preparing classes, and in fact you'll have to if you want to keep doing any of that exciting research that you were so gung-ho about all those years ago. In fact, you'll have to work in the evenings and on weekends and forgo many of that generous number of holidays you've been given, even if you don't bother to try and get any research done. And meanwhile the "losers" who quit appear to be living in much bigger houses in much swankier suburbs, and instead of getting "free trips" to glamourous locations to attend conferences, they can afford to spend their own money to go to the same places to see tourist sites other than the local convention centre. The only perk you seem to be left with is that you don't have to wear a suit -- at least not until you're put on an academic advisory panel, or a university committee, or... Ok, in the end, you probably get the suit as well.

At this point, we discover the true reason why all of that intellectual cannon fodder is necessary: to make us academics feel better. So long as there's a steady stream of suckers who we can ensure will always, deep down, bitterly regret that they can't be like us, we can live with the fact that they have otherwise much better lives.